1. Field of the Invention
The invention relates to a light-emitting device.
2. Related Art
A conventional light-emitting device is known that a silicone resin excellent in gas-barrier property is used as a sealing material for sealing a light-emitting element (see, e.g., JP-A-2009-81430).
According to JP-A-2009-81430, use of the sealing material excellent in gas-barrier property prevents sulfur-based gas or chlorine-based gas from entering into the device and it is thus possible to prevent discoloration caused by corrosion from occurring on a lead frame to which the light-emitting element is connected. A decrease in emission intensity of the light-emitting device caused by a decrease in reflectivity of the lead frame can be prevented by preventing the discoloration of the lead frame.
In JP-A-2009-81430, the crosslink density of the silicone resin was examined by measuring an average spin-spin relaxation time of 1H nuclei using pulse NMR and the gas-barrier property was evaluated. The shorter the average spin-spin relaxation time of 1H nuclei is, the higher the crosslink density is and the more excellent the gas-barrier property is.